Centrifuge apparatus



Aug. 2, 1960 Filed Sept. 20, 1944 C. SKARSTROM CENTRIFUGE APPARATUS 3 Sheets-Sheet l INVENTORS CHARLES SKARSTROM HAROLD C. UREY KARL COHEN ATTORNEY Aug. 2, 1960 Filed Sept. 20, 1944 c. SKARSTROM ETAL 2,947,472

CENTRIFUGE APPARATUS 3 Sheets-Sheet 2 Fig. 2

INVENTORS CHARLES SKARSTROM HAROLD C. UREY KARL COHEN ATTORNEY Aug. 2, 1960 c. SKARSTROM ETAL 2,947,472

CENTRIFUGEAPPARATUS PRODUCT 1 2| y INVENTORS WASTE 4 CHARLES SKARSTROEM HAROLD O. U REY KARL OOH E N av- W432, ATTORNEY 2,947,472 CENTRIFUGE APPARATUS Charles Skarstrom, Pearl River, and Karl Cohen, New York, N.Y., and Harold C. Urey, Leonia, N.J., assignors to the United States of America as represented by the United States Atomic Energy Commission Filed Sept. 20, 1944, Ser. No. 554,980

2 Claims. (Cl. 23319) This invention relates to new and useful improvements in centrifuges, and more particularly to centrifuge devices having in association therewith means for causing the flow or circulation therethrough of gases or Vapor mixtures to be separated.

In a network or system comprising a plurality of centrifuges employed for the separation of gaseous or vaporous mixtures, it is necessary to induce forward or reflux flow or circulation of the gases both through the network and the individual centrifuges in order to realize the full benefit of the cumulative separation of the several centrifuges. In the past, this has been accomplished by providing suitable pumps in the flow passages or pipes between and independently of the several centrifuges in the system. This requires a substantial amount of equipment together with the added disadvantage of numerous glands, bearings and rotating parts, the presence of which materially increases the problems in respect to preventing leakage of the process gases from the system, problems that become extremely important from the economic standpoint and from the aspect of safety in the cases of process gases that are highly corrosive, toxic or poisonous. Also, the initial and maintenance costs of such an installation are quite high.

In accordance with the present invention, however, there is provided a centrifuge having in association or combination therewith one or more centrifugal pumps carried directly upon the shaft of each centrifuge, thereby eliminating a large number of the otherwise necessary equipment and power together with the numerous glands, bearings, and rotating parts incident thereto.

With the foregoing in mind, the principal object of the invention is to provide a centrifuge having one or more centrifugal pumps mounted upon the centrifuge shaft for rotation therewith.

Another object of the invention is to provide a novel combination of a centrifuge and one or more flowinducing pumps, as set forth, whereby the number of glands, bearings and other rotating parts is substantially minimized and the problem of process gas leakage materially reduced.

A further object of the invention is to provide a novel centrifuge and pump combination that embodies certain novel features of construction and arrangement designed to provide a high factor of safety in systems in which employed, and at the same time reduce substantially the initial maintenance and the operating costs of such asystem.

These and other objects of the invention, and the various features and details of construction and operation thereof, are hereinafter fully set forth and described and shown in the accompanying drawings, in which:

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Fig. 3 is a partial view in section taken on line 3-3, Fig. 2; and

Fig. 4 is a schematic diagram of one embodiment of a multistage separating system employing a plurality of centrifuge and pump devices according to the'present invention.

Referring now to the drawings and particularly Figs. 1 and 2 thereof, a centrifuge made in accordance with the present invention may, for example, comprise a centrifuge housing 1 and a pump housing or casing 2 secured in relatively spaced relation endwise of said housing 1 by means of suitable structural members 3.

-Within the housing 1 there is rotatably mounted a separating chamber 4 having a tubular shaft 5 extending axially therethrough. The upper end of the shaft 5 extends through an opening 6 in the top portion of the housing 1 where it is journalled in a suitable bearing 7 and the lower end portion of the shaft 5 extends through the opposite end of the housing 1 and into the pump casing 2 where it is supported in a manner hereinafter set forth. Secured in the lower end of the chamber 4 for rotation therewith, and arranged in spaced concentric relation coaxially of the tubular shaft 5, is a larger tubular shaft 8 that is journalled in the housing bottom wall by means of a bearing 9, and this shaft 8 likewise extends downwardly into the pump casing as shown.

In the centrifuge illustrated, gaseous or vaporous mixtures to be separated are adapted to enter the separated chamber 4 at the upper end thereof through the upper portion of the tubular shaft 5 under the control of a suitable valve 10. For this purpose the shaft 5 is plugged as indicated at 11, and a series of openings 12 are provided therein that open to the interior of the chamber 4 adjacent the top thereof.

In order that the gases entering the chamber 4 through the shaft openings 12 -may be directed to, and pass through, Zones of the chamber '4 relatively remote from the axis thereof, asindicated by the several arrows in Fig. l, a core 13 may be disposed within said chamber and mounted upon the shaft 5 for rotation therewith. Thus, the heavier fraction of the entering mixture will be caused to flow downwardly through the chamber 41 substantially adjacent the periphery thereof, while the lighter fraction of said mixture passes closer to the surface of the core 13.

Secured upon the tubular shaft 5 intermediate the core 13 and the lower end wall of the chamber 4, and relatively spaced as shown with respect to each thereof, is a bafiie member 14 that operates to direct the outer heavier separation fraction into and through the tubular shaft 8 and the lighter separation fraction into the inner tubularshaft 5 through suitable openings 15 therein, as indicated by the arrows in Fig. 1.

The shafts 5 and 8, together with the separating chamber4 carried thereby, are rotationally driven at the required speed by any suitable drive mechanism such as, for example, a pulley 16 secured on said shaft 8 intermediate the housing 1 and pump casing 2, and driven by a belt or the like from a suitable power source.

As shown best in Fig. 2 of the drawings, the pump casingZ is provided with a horizontal partition 17 that serves to subdivide the interior thereof into relatively superimposed pump chambers 18 and 19, respectively. The outer concentric shaft 8 is journalled, and suitably packed against fluid leakage, in the top wall portion of the pump casing 2 and, in accordance with the invention, a centrifugal pump 20 is fixedly secured on the lower end of said shaft 8 for rotation therewith Within the pump chamber 18. The inner concentric shaft 5 extends downwardly beyond the shaft Sand is similarly jour- 21 associated witheach centrifuge.

3 nalled and packed'in the casing partition 17. A second centrifugal pump 21 is fixedly secured upon the lower end of the shaft, 5 "for rotation therewith within the pump names? "19, and the completeshaft and pum assembly is supported at the lower wallportiori 22-of the casing 2 ,by means of a suitable journal and thrust bearing 23. f' f, Fig.3 of the .drawi n g illustrat'e's' one form of centrifugal pump construction that is satisfactory inoperati'on and meets therequirements' for Ia centri'fu'ge of the type described. As will be observed these pumps are of circular, disk-likeconiiguration having a centralannular chamber portion and 25,Irespectively,,therein, trom which extendsa plurality ofjradially extending passages 26 and 27 arranged circumferentially an equally spaced intervals. "The pumps wand 21 may be provided with axiallylextending hub ,portiohs 28 and 28 at opposite sides thereofjarrangedtoembrace snugly the shaft 8 or shaft 5, as the case may b e', .and these hub portions may be threaded .exteriorly to receive ring units or caps' 30 that serve to secure the pumps rigidly upon their respective shafts .for rotation therewith. 'Suitable discharge ports 31 and 32 are provided for the respective pump chambers 18 and 19, to which may be connected pipes or tubing 33 and 34, respectively, for conducting the separation fractions, for example, to another centrifuge stage, or elsewhere, asmay be desired, said pipes or tubing 33 and 34 being provided, respectively, with suitable valves 35*and 36- operable to regulate both the total gas flo-wand the relative proportions of the flow of the separation-fractions from the pump chambers 18 and 19, to obtain optimum results from the separation process.

In operation of a centrifuge ofthe type illustrated that embodies the present invention, gases to be separated by the centrifugal forces generated by the speed of rotation of the chamber 4, and its shafts 5 and 8, are introduced into said chamber through the upper end of the shaft 5 and the openings 12 therein. These inflowing gases are directed laterally by the end of core 13 toward the periphery of the rotating chamber 4 where the centrifugal forces cause a relative separation of the gases with the result that the heavier fraction passes downw-ardly through the chamber 4 adjacent the outer peripheral wall thereof while the lighter separation fraction travels an inner path closer to the surface of said core 13; Passage of the separation fractions through the chamber 4' is inducedby thecentrifugal pumps 20 and 21, the pump 20 operating to draw off the heavier separation fraction from chamber 4 through the shaft 8 and discharge that fraction under elevated pressure through the port 31 and pipe33by which it is conducted to a succeeding centrifuge stage, or elsewhere, depending upon the particular separation system employed, While the pump 21 operates to draw off the lighter separation fraction through the shaft 5 and discharge it at an elevated pressure through the port 32 and pipe 34.

Fig. 4 of the drawings is a schematic illustration of a typical separation system comprising a plurality of interconnected centrifuges -A, B, C and D, made in accordance with the present invention, that may be selectively employed to produce a concentrate of a desired gas from a gaseous mixture. In this particular system, gases from each of the reservoirs 37 and 38 are introduced into the [first and fourth centrifuges. A and D, respectively, wherein said gases are separated in the manner herein above described. In each of these centrifuge stages, the heavier and lighter separation fractions-are drawn olf .by the centrifugal pumps 20 and In the illustrated system, the pump 20 of the centrifuge A discharges the heavier. separation --fraction to thejnlet of. the second centrifuge. .B..and.the. pump. 21 returns the lighter separation fraction to the reservoir 38 for recirculation and 4 a the corresponding pump 21 delivers the lighter separatio fraction to the inlet of the third centrifuge C.

The centrifuge C has its pump 20 connected to return the heavier separation fraction also to the reservoir 38 for recirculation and the pump 21 thereof delivers the lighter fraction to the inletpfthe centrifuge B where it is mixed with theheavier fraction produced in the centrifuge A. The heavier traction of centrifuge B is delivered by its pump lilto the inlet to centrifuge fl where said fractionis mixed with the lighter fraction from centrifuge D for reseparation, Similarly, the lighter fraction'from centrifuge B is delivered to the inlet of centrifuge A where it mixes with gases from the reservoir 37 fofreprocessing.

In the particulanmulti-stage separation system shown, the end product may be drawn off from the return line to the reservoir 37 and the waste may be drawn off the other return line that leads to the reservoir 38 from the pump 20 of the'centrifuge D. As previously stated, dis charge from each of the pumps 20 and 2 1 is controlled by a suitable valve 35 and 36, respectively, that may be operated to regulate the total and relative proportions of the separation in order to produce optimum separation results.

From the foregoing, it will be apparent that the present invention provides a centrifuge and pump construction that may be employed in a multi-stage gas separation system to induce forward and reflux circulation of the gases both through thersystem and the individual centrifuges and thereby obtain the full benefit of the cumuiative separation of the several stages of the system by minimizing leakage and loss of the process gas through substantial elimination of the numerous glands, bearings and additional rotating parts that would be inherent in'the use of a number 'of independent pumps located intermediate theseveral centrifuge stages of the system. Also, the present invention, in addition to 'increasing the operating efiiciency of the system by minimizing leakage of the process gas also provides a substantially higher safety factor for such a system in cases Where the process gas is characterized by its corrosive, toxic or poisonous properties. -Furthermore,the present invention provides a centrifuge and pump construction that is advantageous from the standpoint of economy in the cost of installation, operation and maintenance.

It should be stated that the present invention is not limited to the particular form and construction of centrifugal pump shown and described but that numerous other centrifugal pump constructions may be employed satisfactorily in accomplishment of the purposes and teachings of the present invention. Also it is to be borne in mind that While a particular embodiment of the invention has been shown and described, it is not intended to limit the invention to such disclosure, and changes and modifications may be made or incorporated within the scope of the claims.

We claim:

1. A centrifuge device for separating fluid mixtures comprising a rotatable separating chamber, a first tubular shaft providing an inlet and outlet to said chamber at respectively opposite ends thereof extending axially of said chamber, a second tubular shaft arranged in concentric spaced relation with respect to the first shaft outlet portion and providing a second outlet from the chamber, means for rotationally driving said shafts and chamber, a cylindrical core surrounding and arranged to rotate with the first tubular shaft, said core being positioned intermediate the inlet and outlet portions of said first shaft, a baffle in said chamber arranged to separate the outlet portion of said first shaft from the outlet portion of said second shaft and operable to cause the heavier separation .fractionxin said chamber to flow outwardly from the chamber'uthroughlthe second ,shaftqand the lighter separation fraction to flow outwardly through the first-shaft outlet portion, and a centrifugal pump secured on each of said shafts for rotation therewith, said pumps each having its intake communicating with the interior of its shaft and operating during rotation of the device to induce flow of the respective separation fractions through the chamber and deliver the said fractions under pressure at a point exteriorly of said device, valve means operable to control the amount of fluid admitted to said chamber through said first shaft inlet portion, and valve means operable to control the amount and relative proportions of the separation fractions discharged from each pump.

2. A centrifuge device for separating fluid mixtures comprising a rotatable separating chamber, a first tubular shaft providing an inlet and outlet respectively to said chamber at opposite ends thereof and extending axially of the chamber, a second tubular shaft arranged in spaced concentric relation with respect to the first shaft outlet portion and providing a second outlet from the chamber, means for rotationally driving said shafts and chamber, a cylindrical core surrounding and arranged to rotate with the first tubular shaft, said core being positioned intermediate the inlet and outlet portions of said first shaft, a baflie in said chamber arranged to separate the outlet portion of said first shaft from the outlet portion of said second shaft and operable to cause the heavier separation fraction in said chamber to flow outwardly from the chamber through the second shaft and the lighter separation fraction to flow outwardly through the first shaft outlet portion, a stationary casing having adjacent compartments therein each provided with a discharge port, said second shaft and the first shaft outlet 6 portion extending respectively into said adjacent casing compartments and being rotatable with respect thereto, and a centrifugal pump secured on each of said shafts for rotation therewith in the respective casing compartments, said pumps each having its intake communicating with the interior of its shaft and operating during rotation of the device to induce flow of the respective separation fractions through the chamber and deliver the said fractions under pressure outwardly of the discharge ports of said compartments, valve means operable to control the amount of fluid admitted to said chamber through said shaft inlet portion, and valve means operable to control the amount and relative proportion of the separation fractions discharged from the respective casing ports.

References Cited in the file of this patent UNITED STATES PATENTS 1,061,656 Black May 13, 1913 1,257,235 Howell Feb. 19, 1918 1,700,928 Fawkes Feb. 5, 1929 1,731,313 Miller Oct. 15, 1929 1,870,113 Hawkins Aug. 2, 1932 2,107,035 Hall Feb. 1, 1938 2,145,544 Hapgood Jan. 31, 1939 2,223,999 Miller Dec. 3, 1940 2,227,837 Lindgren Jan. 7, 1941 2,403,089 Lars July 2, 1946 FOREIGN PATENTS 691,386 Germany May 24, 1940 

